/***************************************************************************
 * Copyright 2012 TXT e-solutions SpA
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * 
 * This work was performed within the IoT_at_Work Project
 * and partially funded by the European Commission's
 * 7th Framework Programme under the research area ICT-2009.1.3
 * Internet of Things and enterprise environments.
 *
 * Authors:
 *      Salvatore Piccione (TXT e-solutions SpA)
 *      Carbone Matteo
 *
 * Contributors:
 *        Domenico Rotondi (TXT e-solutions SpA)
 **************************************************************************/
package it.txt.ens.authorisationService.amqp;

import java.io.IOException;

import com.rabbitmq.client.Channel;

/**
* This class encapsulates the management of an AMQP exchange.
* 
* @author Carbone Matteo
* @author Salvatore Piccione (TXT e-solutions SpA - salvatore.piccione AT network.txtgroup.com)
*/
public class AMQPExchangeHelper{
	
	public AMQPExchangeHelper(){}
	
	/**	
	 * Creates a new exchange
	 * @throws IOException 
	 */
	public void creates(Channel channel, String exchange) throws IOException{
		channel.exchangeDeclare(exchange, "topic", true);
		
	}
	
	/**	
	 * Creates a new exchange
	 * @throws IOException 
	 */
	public void creates(Channel channel, String exchange, String type, boolean durable, boolean autoDelete) throws IOException{
		channel.exchangeDeclare(exchange, type, durable, autoDelete, null);
	}
	
	/**	
	 * Deletes an exchange
	 * @throws IOException 
	 */
	public void delete(Channel channel, String exchange) throws IOException{
		channel.exchangeDelete(exchange);
	}
	
	/**
	 * Checks the existence of an exchange 
	 * 
	 * @param channel
	 * @param exchange
	 * @return
	 */
	public boolean exists (Channel channel, String exchange) {
	    try {
            channel.exchangeDeclarePassive(exchange);
            return true;
        } catch (IOException e) {
            return false;
        } finally {
        }
	}
}